Why create any order of precedence at all?

All can be equal in your eyes, all important. Then you get to choose based on circumstances and events.

If you create a precedence, you loose the ability to weigh, consider and choose. Is picking up your daughter from a sleep-over because she's bored more important than spending a night alone with him?

Will you always cook her favorite food and never his?

Would you create a situation like this if it were just you and your child in the equation?

My point is, why worry about "who comes first" in your life and instead live your life and lives together as circumstances dictate and require. Then perhaps, such questions either need not be asked... or are easily answered by you.